GB2617680A

GB2617680A - Improvements in or relating to a colonial-seabird nesting and feeding structure

Info

Publication number: GB2617680A
Application number: GB2302249.4A
Authority: GB
Inventors: Charles Burden Trevor; Jo Stevenson Nathalie
Original assignee: Shoney Seonaidh Wind Ltd; Francis and Lewis International Ltd
Current assignee: Shoney Seonaidh Wind Ltd; Francis and Lewis International Ltd
Priority date: 2021-03-12
Filing date: 2021-03-12
Publication date: 2023-10-18
Also published as: GB202302249D0

Abstract

A method of siting and assembling a colonial-seabird nesting structure 10 with a plurality of seabird support elements by determine a geographic location and an orientation of the support elements. The geographic siting location may be determined based on colonial seabird biology data, position of a body of water or building relative to the nesting structure, terrain data, topography, time series data about wind, solar irradiation, sun path, sun azimuth, sun elevation, shade or proximity to existing colonial seabird populations, predators or habitats suitable for a predator. The orientation of the support elements may be determined based on temperature, wind, rain or sun exposure, visibility of a body of water and/or a protective side wall of the support elements. The seabird support elements may face in the same or different directions. The structure may be altered by moving it, or adding or removing a protective side wall, viewing element, window, capture device or feeding aperture. The structure is also claimed.

Description

Improvements In Or Relating To A Colonial-Seabird Nesting and Feeding Structure The present invention relates to a bird-population compensation structure for at least in part managing local, regional, national, or worldwide bird populations to compensate for bird losses elsewhere. The present invention also relates to a colonial-seabird nesting structure for at least in part increasing breeding productivity and providing a safe access space for a user. The invention also pertains to a method for identifying a suitable site and orientation of a bird-population compensation structure or a colonial-seabird nesting structure.

The term "bird" used herein and throughout is intended to refer to a warm-blooded egg-laying vertebrate animal having wings and a beak at any stage of life. Thus, the term "bird" encompasses an egg, a chick, a young bird or juvenile, a fledgling, a breeding adult, and a non-breeding adult. A young bird may be considered to a bird from a hatched chick through to fully fledged chick which has departed the nest.

Offshore wind farms have the potential to cumulatively reduce some seabird populations due to seabird mortality from collisions with turbine blades. Particular impacted species include seabirds, and more specifically colonial seabirds, such as Kittiwakes, Gannets, and Fulmars. As a result, many wind turbine construction projects fail to secure regulatory permits due to conservation concems.

Conservation concerns around loss of seabird nesting sites also arise from other projects 20 such as, demolition, refurbishment or development of harbours, ports or piers which may result in loss of nesting habitat for colonial seabirds, with knock-on effects on breeding success which potential may result in local, regional or worldwide population reduction.

A solution to the wind farm induced mortality and/or loss of nesting sites associated with coastal developments is to provide replacement artificial nesting habitat and undertaking supplemental feeding of colonial seabirds to improve breeding productivity Existing solutions include erecting permanent artificial cliff-like structures onto natural cliffs to provide additional nesting sites. However, these structures have drawbacks. They are difficult to access for maintenance and require the use of heavy plant and equipment. Once constructed they cannot be relocated, and reassembled in another location. They are not modular and adaptable. Food availability is not improved. Exposure to the elements such as wind, rain, and sun result in some sides of the artificial cliff-like structures being sub-optimal or unusable as nesting sites.

Monitoring the movements of colonial seabird species, such as via tagging or ringing individuals is also desirable, and in some instances, a legal requirement for conservation purposes. However, monitoring via tagging or ringing in natural nesting habitats is difficult or impossible due to challenging access issues for species that nest in inaccessible or substantially inaccessible habitats, such as on cliff faces.

Furthermore, the existing solutions do not enable safe and easy human access for monitoring purposes.

The present invention seeks to provide a solution to these problems.

According to a first aspect of the present invention, there is provided a colonial-seabird nesting structure for at least in part increasing breeding productivity and providing a safe access space for a user, the colonial-seabird nesting structure comprising: a user-access element having at least one wall comprising an access opening, the at least one wall defining a user-access area of the user-access element; a closure element for openably closing the access opening in the said wall, the closure element having: a colonial-seabird facing first surface which in use faces outwardly to the ambient environment, a user-facing second surface which is opposite the first surface and which in use faces inwardly towards the user-access area, a colonial seabird-support element extending from the said first surface and which is adapted to support at least one bird and/or bird-nesting structure thereon, a capture-device aperture for enabling insertion of a bird-capture device therethrough to temporarily capture a bird supported by the colonial seabird-support element, and an openable viewing element that can be opened to retrieve a captured bird; the closure element being movable relative to the access opening to enable the colonial seabird-support element to be selectively movable into the user-access area.

The structure enables offsetting of increased mortality, whether predicted or actual, 25 and/or reduced population sizes of colonial seabirds due to coastal industrial activities such as port and harbour development. The structure also provides an easy and safe access for a human user.

Breeding productivity can be measured as one or more of: clutch size, nesting success, number of clutches laid per year, number of juveniles fledging, or any other metric. 30 Juvenile fledging is defined as young birds departing the nest to join the adult population.

According to a second aspect of the present invention, there is provided a bird-population compensation system for at least in part managing a bird population, the bird-population compensation system comprising: a support structure supporting at least one wall comprising an access opening, the at least one wall defining a user-access area of the support structure; a closure element for openably closing the access opening, the closure element having: a bird-facing first surface which in use faces outwardly, a user-facing second surface which is opposite the first surface and which in use faces towards the user-access area, and a bird-support element extending from the first surface and which is adapted to support at least one bird and/or bird-nesting structure thereon; the closure element being movable relative to the access opening to enable the bird-support element to be selectively movable into the user-access area for safe access by a user.

The term "bird-population compensation structure" used herein and throughout is preferably intended to mean a structure that may increase any of: the breeding productivity, the survival rate, and the size of a bird population in order to compensate for or offset an increased mortality and/or a reduced population size of the same bird species elsewhere.

The term "bird population" used herein and throughout may be used to refer to a group 15 of individuals of a same bird species. The population may be a local population, a regional population, a national population, or a worldwide population.

The colonial-seabird nesting structure, which may also be referred to as a bird-population compensation structure and/or as a bird-population compensation system, enables a compensation scheme for industrial applications. In other words, the structure may enable offsetting of increased mortality and/or reduced population size of birds, and more preferably colonial seabirds, due to industrial activities. More particularly but not necessarily exclusively, increased bird injury and mortality due to wind turbines can be compensated, enabling these projects to be approved. The support structure provides a safer, and more easily accessible platform for scientists to access and monitor birds. The mobility of the closure element enables a user to have easier access to the bird-support element or colonial seabird-support element. In turn, it is easier to clean the bird-support element or colonial seabird-support element.

It may easily be envisioned that a colonial-seabird-or, more broadly, bird-population compensation structure may also be used without necessarily being required to offset or 30 compensate a higher bird mortality elsewhere, whether actual or projected.

Preferably, the structure may further comprise a tower element for supporting at least the user-access area. The term "tower element" used herein and throughout is intended to mean a, preferably tall, assembly or structure, and which may alternatively be referred to as a shell structure, a spatial structure, or a space structure. The term 'spatial structure' is understood to include but not be limited to towers, such as lattice towers, tower-like structures, and any other similar, preferably load-bearing, structures.

Beneficially, the closure element may comprise a further viewing element. This feature enables a user to observe a bird through the viewing element. Additionally or 5 alternatively, the viewing element may enable a user to reach therethrough to the bird-or colonial seabird-support element and/or to a bird thereupon.

Optionally, the or each viewing element may be closable by a window element. A window element provides a barrier, preventing or inhibiting the ingress of any of: a bird, bird guano, nesting material, and odours. The window element also provides weatherproofing. A window element is preferably at least partly transparent and/or translucent to enable a user to look through the window element.

The capture-device aperture enables a user to temporarily capture or restrain a bird, for example, to be able to measure biometrics, consult a tag, and/or add a tag to a bird for scientific purposes.

Advantageously, the colonial-seabird nesting structure, preferably in accordance with the first aspect of the invention, or the bird-population compensation structure, preferably in accordance with the second aspect may further comprise a connection means for connecting the closure element to the at least one wall. The connection means provides a structure connecting the closure element to the user-access element or support structure and enabling the closure element to be movable relative thereto. The connection means may also increase the stability of the closure element, compared to a closure element that is disconnected from the wall and/or engageable therewith via interference fit.

Beneficially, the connection means may comprise a pivot axis about which the closure element may be pivotable. Furthermore, the closure element may have a first side or longitudinal edge and a second side or longitudinal edge, and the pivot axis may extend at or adjacent to the first or second longitudinal edge. Additionally, the connection means may comprise at least one hinge. The closure element is hingeably connected or connectable to the wall.

Alternatively, the pivot axis may be positioned spaced-apart from both a first longitudinal edge and a second longitudinal edge of the closure element. Optionally, the pivot axis may be or be substantially equidistant from both longitudinal edges. The closure element may be rotatable about a central axis. In other words, the closure element may be rotated such that the first surface which in use faces outwardly, temporarily faces inwards, at least in part, and be simultaneously receivable within or substantially within the access opening. This enables the colonial seabird-support element or the bird-support element to temporarily extend into the user-access area. The closure element may be movable 5 with respect to the wall without requiring to be moved into the user-access area. The closure element being rotatable about a central axis may also be safer. When the bird-support element or colonial seabird-support element extends in and/or towards the user-access area, the closure element continues to at least partly close the access opening. This reduces the risk of a user falling through the access opening. Additionally, if the 10 user-access area is heated, such a closure element may prevent or inhibit heat losses by reducing the time the access opening is open.

In a further alternative, the first longitudinal edge may be spaced apart from the second longitudinal edge by a width and the pivot axis may be positioned at or adjacent to, for example, a third of the width from one of the longitudinal edges. Other spacings other than a third may be considered. This may enable the closure element to be at least partly pivoted inwards into the user-access area.

Optionally, the connection means may comprise a translation means for enabling translation of the closure element relative to the access opening. The closure element may be translatable, preferably linearly, inwards into the user-access area. The closure element may or may not be pivotable. Linear translation inwards may be advantageous in case any birds, whether the target species or a predator thereof, are present on the or a further bird-support element or colonial seabird-support element. If one or more birds are spooked, they may attempt to fly off. As the bird-support element or colonial seabird-support element is oriented outwardly, the bird has an increased likelihood of flying off into the ambient environment, rather than into the user-access area. Preferably, the closure element is only moved when no bird is present on the bird-support element, but this is optional such that the closure element may be moved when at least one bird is present on the bird-support element.

Preferably, the colonial-seabird nesting structure, preferably in accordance with the first aspect of the invention, or the bird-population compensation structure, preferably in accordance with the second aspect may further comprise a railing element which may extend or be configurable to extend across the access opening. The railing element increases safety by inhibiting or preventing a user from falling from the structure.

Advantageously, the closure element may further comprise a feeding aperture for providing food therethrough. Providing additional food increases breeding productivity of a bird. Some bird species, such as kittiwakes, may have restricted time-activity budgets compared with other species of bird. When natural food resources are scarce in marine and tidal waters, individual adult birds may need to compensate for lower food availability by travelling further in search of suitable prey. This requires additional energy expenditure and increases the time between chick feeding. When the additional energy requirements exceed energy obtained from food, this is unsustainable in the long term and results in reductions in breeding productivity, and/or nest abandonment. Supplemental feeding can counter this. Furthermore, certain types of high-quality energy food, such as lipid-rich food may be naturally limited at sea during the breeding season. Supplemental feeding of lipid-rich and/or energy-rich food sources such as, but not limited to sandeel, herring and sprat via the feeding apertures will increase body energy stores within birds. Higher stored lipid content in adult birds and young chicks improves thermoregulation and survivability. Furthermore, supplemental feeding reduces siblicidal aggression between chicks, resulting in improved survivorship of all chicks that hatch compared with the death of the second, third or later-born chicks when food quality or availability is naturally lower in coastal waters.

Furthermore, the closure element may further comprise a drainage hole at or adjacent the bird-support element or the colonial seabird-support element. A drainage hole or conduit, or evacuation conduit enables water, such as rainwater, and any other liquid to be evacuated, rather than stagnate. Nest waterlogging, which negatively affects egg and/or chick survivability, is reduced.

Optionally, the closure element may further comprise a protective side wall. Preferably, the protective side wall may be positioned or positionable at or adjacent a lateral edge of the bird-support element or the colonial seabird-support element. The side wall provides protection against adverse weather effects, such as wind, rain, sun; and/or predators.

Additionally, or alternative, the or a further protective side wall may be positionable spaced-apart from a lateral edge of the bird-support element or the colonial seabird-support element. The side wall may also partition the bird-support element or colonial seabird-support element to provide a plurality of discrete sub-sections, each sub-section for receiving at least one bird, and more preferably a colonial seabird nesting pair and/or the nest thereof. Each sub-section may be referred to as a nest or nesting-surface. The protective side wall may be referred to as a partition. The or each side wall, irrespective of its location, may be removable. The or each side wall may also optionally improve the structural strength of the bird-population compensation structure or colonial-seabird nesting structure.

Advantageously, the or at least one said protective side wall may comprise an at least 5 partly light-transmissible material. Adjacent birds on either side of a transparent or translucent side wall may see each other which increases social stimulation and/or breeding synchrony and will enable a nesting bird to see a body of water therethrough. Additionally, a light-transmissible side wall lets light, and therefore heat through, whilst providing a windshield. The additional warmth may increase breeding productivity of 10 birds, particularly if the bird-support element or colonial seabird-support element extends in an unfavourable orientation, thereby birds and/or nests being exposed to wind and/or cold such as due to shade.

Optionally, the bird-support element or the colonial seabird-support element may meet the first surface at an acute angle. An acute angle may reduce exposure of the nests to 15 direct wind chill and rain. Furthermore, the likelihood of a bird, such as a chick, falling off the bird-support element or colonial seabird-support element may be reduced.

Beneficially, the colonial-seabird nesting structure, preferably in accordance with the first aspect of the invention, or the bird-population compensation structure, preferably in accordance with the second aspect may further comprise a staircase which may be associated with the user-access element. A user can walk up and down stairs to access the user-access area, rather than necessitating climbing skills to climb up and/or abseil down an outer surface of the structure, or requiring an external device having a movable platform such as a cherry-picker, or the use of ladders and associated safety elements.

Furthermore, the colonial-seabird nesting structure, preferably in accordance with the first aspect of the invention, or the bird-population compensation structure, preferably in accordance with the second aspect may further comprise a climbing anchor element for enabling climbing equipment to be engageable therewith. The climbing anchor element may be used by users having suitable climbing qualifications, for example, during maintenance structural inspections.

According to a third aspect of the present invention, there is provided a method of siting and assembling a colonial-seabird nesting structure, optionally in accordance with the first aspect of the invention, the method comprising the steps of: a] providing a colonial-seabird nesting structure having a plurality of colonial seabird-support elements, preferably facing in the same and/or in different directions optionally once assembled; b] determining a geographic siting location based on one or more of: colonial seabird biology data; position data of a body of water and/or a further building relative to the colonial-seabird nesting structure; terrain data; topography data; time-series data about at least one of: wind, solar irradiation, sun path, sun azimuth, sun elevation, and shade; proximity to an existing colonial seabird population; proximity to a predator population; and/or proximity to a habitat suitable for a predator; c] determining an orientation of the said colonial seabird-support elements of the colonial-seabird nesting structure depending on one or more: temperature, wind exposure, rain exposure, sun exposure, visibility of the or a body of water from at least one said colonial seabird-support element, and/or the provision of a colonial seabird-support element with at least one protective side wall; and d] assembling the colonial-seabird nesting structure at the determined geographic siting location and with the determined orientation.

Locating an appropriate geographic siting location may be the difference between the bird-population compensation structure being used by birds and remaining empty.

Orientation is another important factor influencing the decision of a breeding pair to attempt to breed on a structure, and/or influencing the subsequent breeding productivity of the breeding bird or pair of birds.

According to a fourth aspect of the present invention, there is provided a method for siting and assembling a bird-population compensation structure, optionally in accordance with the second aspect of the invention, the method comprising the steps of: a] providing a bird-population compensation structure; b] selecting a geographic siting location based on at least one environmental and/or biological parameter; c] determining an orientation of at least one bird-support element of the bird-population compensation structure depending on at least one of: temperature, wind exposure, rain exposure, sun exposure, visibility of a body of water from a said bird-support element, and the provision of a bird-support element with a protective side wall; and d] assembling the bird-receiving compensation structure at the determined geographic siting location and with the determined orientation.

Location and orientation are important factors influencing the use or uptake of the bird-30 population compensation structure by birds and more preferably breeding pairs, and their subsequent breeding productivity.

Optionally, the method, preferably in accordance with the third and/or fourth aspects, of the invention may comprise a further step of altering the colonial-seabird nesting structure or bird-population compensation structure by at least one of: moving the structure or part thereof; adding any of: at least one protective side wall, at least one bird-support element or colonial seabird-support element, at least one viewing element, at least on window element, at least one capture-device aperture, at least one feeding aperture; and removing any of: at least one protective side wall, at least one bird-support element or colonial seabird-support element, at least one viewing element, at least on window element, at least one capture-device aperture, at least one feeding aperture. The whole of the colonial-seabird nesting structure or bird-population compensation structure, or any part thereof may be dismantleable and/or movable after assembly. This enables the structure to be relocatable. The colonial-seabird nesting structure or bird-population compensation structure may therefore be modular and/or adaptable. The ability to alter the orientation and/or the configuration of each closure element enables a user to carry out experiments. For example, the ability to add or remove a protective side wall enables the user to assess the effect of the side wall on breeding productivity. The user can also assess the relative importance of being able to view the body of water from a bird-support element or colonial seabird-support element. The structure can be increased in height by addition of one or more further support structures or user-access elements, allowing for the addition of further nesting space to increase available capacity for birds, and more preferably colonial nesting seabirds.

The invention will now be more particularly described, by way of example only, with 20 reference to the accompanying drawings, in which: Figure 1 shows a perspective representation of a first embodiment of a bird-population compensation structure in accordance with the first and second aspects of the invention, in an assembled condition; Figure 2 illustrates a close-up perspective representation of two walls of a cabin 25 of the bird-population compensation structure of Figure 1; Figure 3 represents a close-up perspective representation of two further walls of the cabin and a roof element of the bird-population compensation structure of Figure 1; Figure 4 illustrates a close-up perspective view of an anti-climbing portion of the bird-population compensation structure of Figure 1; Figure 5 shows a close-up perspective representation of an embodiment of a foundation element of the bird-population compensation structure of Figure 1; Figure 6 shows a close-up perspective photo of a further embodiment of a foundation element of the bird-population compensation structure of Figure 1; Figure 7 shows a top plan representation of a further embodiment of a foundation element of the bird-population compensation structure of Figure 1; Figure 8 shows a side representation of the foundation element of Figure 7; Figure 9 represents a close-up perspective representation of closure elements of 5 the bird-population compensation structure of Figure 1, viewed from within a user-access area; Figure 10 illustrates a close-up perspective representation of parts of closure elements of the bird-population compensation structure of Figure 1, viewed from outside; Figure 11 shows a close-up perspective representation of part of a closure 10 element of the bird-population compensation structure of Figure 1, viewed from outside and having protective side walls; Figure 12 illustrates a close-up perspective representation of the bird-population compensation structure of Figure 1, in-use, in which bird-support elements are received within the user-access area by inward rotation of the closure element; and Figure 13 shows a perspective representation of a second embodiment of a bird-population compensation structure in accordance with the first and second aspects of the invention, in an assembled condition, the bird-population compensation structure having two cabins.

Referring firstly to Figure 1, there is shown a bird-population compensation structure 20 indicated generally at 10. The bird-population compensation structure 10 enables managing at least in part a bird population. The bird-population compensation structure 10 may do so by boosting or increasing the breeding productivity of a bird species in use.

During the nesting season, the bird-population compensation structure 10 provides at least one nesting site, thereby increasing the available nesting habitat. However, the bird-population compensation structure 10 may still provide a habitat for supporting at least one bird outside of the nesting season. The at least one bird may be of the same species or of a different species.

The bird-population compensation structure 10 may accommodate one species or a plurality of species. The species are preferably protected bird species, but any non-protected bird species may be accommodated. Preferably, the structure 10 is more suitable for birds that form colonies, in other words, colonial birds, but non-colonial species may be accommodated instead or in addition, such as solitary birds. The bird species may be a species relying on a body of water. The body of water may be a marine body of water, freshwater, or brackish water, any of which may be tidal or non-tidal. The body of water may include inland tidal rivers and estuaries, and marine/coastal waters.

Preferably, the body of water excludes freshwater rivers, streams, ponds or lakes but it 5 could easily be envisioned that the body of water does encompass any of the above.

Preferably, the bird-population compensation structure 10 is best suited for seabirds. Most preferably, the bird-population compensation structure 10 is best suited for colonial seabirds. Colonial seabirds include but are not limited to: Kittiwakes, Gannets, and Fulmars, The bird-population compensation structure 10 may be referred to as a structure, a system, a bird nesting structure, a seabird nesting structure, a seabird compensation structure, a colonial-seabird nesting structure, a colonial seabird compensation structure, a bird receiving structure, or an artificial cliff.

The bird-population compensation structure 10 or any part thereof may comprise any of 15 metal; plastics; concrete; wood, such as but not limited to plywood; glass; any other material; and any combination of the above. Preferably, the materials are recycled and/or recyclable but this is optional.

The bird-population compensation structure 10 has a user-access element 12, and at least one closure element 14. In the shown embodiment, the bird-population 20 compensation structure 10 has twelve closure elements 14, as shown in Figures 2 and 3.

The user-access element, accessible element or support structure 12 has at least one face, wall section or wall 16. More preferably as shown, the user-access element 12 has four walls 16 but any number may be envisioned. Figure 2 shows two of the four walls 16 and Figure 3 shows the other two walls 16. The walls 16 are planar or substantially planar, but each, any or at least one wall may be non-planar. The user-access element 12 is preferably square or rectangular in lateral and/or longitudinal cross-section but non-square or non-rectangular is an option. Additionally or alternatively to one or more walls, the user-access element 12 may comprise a frame or frame element.

The at least one wall 16 is adjacent to and/or defines a user-access area 18 of the user-access element 12. The user-access area 18 is suitably dimensioned to receive at least one user therein. The user-access area 18 may also be referred to as a user-access space or access space. If the user-access area 18 is covered, such as by having a roof or roof-element, the user-access area 18 may be referred to as an internal user-access area 18. Together, the user-access area 18 and the at least one wall 16 may be referred to as a cabin, a platform, an access cabin, a monitoring cabin, a viewing platform, or a housing 20. There may optionally be a plurality of cabins 20.

Although the term "cabin" has been used herein and throughout for clarity, the term is not intended to be limited to a structure having a roof and a plurality of walls enclosing a space. Instead, the term "cabin" is intended to encompass any structure having at least one wall and a user-access area.

For example, the term is intended to include a first structure which may be or having at least one wall and which is mountable onto a second structure, the first structure being at least partly spaced-apart therefrom to define a volume, gangway or user-access area for receiving a user therein. The user-access area may necessarily not be covered. The user-access area may optionally be or be substantially open at one or more ends. The second structure may include an oil rig, a harbour wall, a pier, an existing wall or any other suitable structure.

The, each or at least one of the said walls 16 preferably has at least one access opening 22, although an access opening may be omitted from any or all the walls. In the shown embodiment, three of the walls 16 have at least one, and more preferably two access openings 22. There are thus six access openings 22 in the preferred embodiment. The access openings 22 may all have similar or identical dimensions. However, at least one access opening may have different dimensions relative to at least one other access opening.

Additionally or alternatively to an access opening 22, one of the walls 16 may comprise at least one lighting aperture or light-permitting opening 21 for permitting light ingress 25 into the user-access area 18, but this is optional. As shown in Figure 2, the, notionally fourth, wall 16 comprises two such light-permitting openings 21.

Each light-permitting opening 21 is similar to an access opening 22 but is preferably devoid of any closure element 14. Each light-permitting opening 21 may be permanently open. Alternatively, one or both light-permitting openings 21 may be closed or closeable, 30 such as by a window.

The user-access element 12 also preferably comprises a roof element 24, a spacer element 26, a foundation element 28, a connection means 30, and at least one staircase 32 but any of these features may be omitted.

The roof element 24 provides a roof for at least part of the cabin 20. The roof element 24 is best shown in Figure 3. Optionally, the roof element 24 may comprise an at least partly transparent and/or translucent material to enable light therethrough, but partly or fully opaque is an option. Permitting light through the roof enables a user to work using natural light. Artificial lighting and therefore, electricity, may be dispensed with. One or more solar panels may be provided if required.

The spacer element 26 spaces the cabin 20 from the foundation element 28 and/or a ground surface. In other words, the spacer element 26 provides height to the cabin 20. The spacer element 26 may alternatively be referred to as a tower element. The bird-population compensation structure 10 is preferably at least ten metres high but any height less than ten metres may be envisioned, such as one, two, three, four, five, six, seven, eight or nine metres high. More preferably, the structure 10 is at least fifteen metres high. In the preferred embodiment, the structure 10 is at least twenty metres high.

The spacer element 26 comprises a spacer-frame or framework 34 in the preferred embodiment, but any alternative, such as one or more walls, may be envisioned. Whilst walls may increase safety for a user climbing within, a spacer-frame 34 may reduce wind resistance. A spacer-frame 34 may also more easily dismantleable and/or assembleable than a wall. A spacer-frame 34 may also be lighter and/or easier to transport. The dimensions of the spacer element 26 may be selectable and/or alterable, for instance if the spacer element 26 is modular. The spacer element 26 may have any height, as required. For example, the spacer element 26 may have a height of between 1 metre and 19 metres, although any value outside of this range may be envisioned. More preferably, the height may be in the range of 2 metres to 15 metres, more preferably in the range of 5 metres to 14 metres, and most preferably is in the range of 8 metres to 10 metres. An advantage of spacing apart the cabin 20 from the ground is that predation by ground predators such as vermin or foxes is prevented or inhibited.

The spacer element 26 and/or the cabin 20 preferably also comprise one or more of the said stairs or staircases 32, but this feature may be omitted. This enables a user to ascend to and/or descend from the cabin 20.

It may easily be envisioned that a lift, dumbwaiter, one or more ladders, or any other means of ascending and descending from the cabin may be provided in addition or instead of the stairs. If ladders are used, a rest platform may need to be periodically provided, such as every 5 metres. A latch way and/or a fall arrest system may also be required in this alternative embodiment.

The staircase is external and/or, preferably, internal. Preferably, the staircases 32 extend through a floor of the cabin 20, as in the present embodiment. However, it may easily be envisioned that the staircase may alternatively provide an ingress to the cabin via a wall.

Optionally, the spacer element 26 may comprise an anti-climbing portion or climb deterrent 36 to prevent or deter unauthorised access to the cabin 20 and/or to the staircase 32. This may be provided as a peripheral wall or walls 37 and/or a lockable door. The anti-climbing portion 36 is preferably at or adjacent to a base of the spacer element 26, as shown in Figure 4. The peripheral wall or walls 37 may optionally be coated with an anti-climbing coating.

Although a spacer element is preferably provided, it may easily be omitted, as required. For example, a cabin may be mountable directly onto the foundation element and/or onto another structure, such as an oil rig, a harbour, a pier, or other pre-existing wall or structure.

The foundation element 28 enables the spacer element 26 and/or cabin 20 to be grounded or anchored to a ground surface, temporarily or permanently. If temporarily, the bird-population compensation structure 10 may be dismantleable and/or movable as required. In other words, the structure 10 may be relocatable. Optionally, the foundation element 28 may comprise a slab or block 38, such as a slab of concrete as shown.

A first embodiment of at least part of a foundation element 28 is shown in Figure 5. The 20 foundation element 28 optionally comprises at least one micropile 39 instead of or in addition to the slab 38. Instead or in addition, one or more micropiles 39 may optionally be usable with a foundation-frame, also referred to as a grillage.

A second embodiment of at least part of a foundation element 28' is shown in Figure 6. The foundation element 28' may comprise a foundation-frame 40 instead or in addition to a slab 38. The foundation-frame 40 may comprise one or, preferably, a plurality of beams 42. The foundation-frame 40 may be useful to distribute the weight of the bird-population compensation structure 10.

A third embodiment of at least part of a foundation element 28" is shown in top view in Figure 7 and in side view in Figure 8, also comprising a foundation-frame 40' and optional 30 slab 38. The foundation-frame 40' also comprises one or more beams 42', in a different arrangement relative to the second embodiment.

The second of the foundation element 28' and/or third embodiment of the foundation element 28" may further comprise one or more piles 43, shown in the third embodiment of the foundation element 28". The foundation-frame 40,40' may be anchorable into the ground via the one or more piles 43. The piles 43 may be screw piles and/or relocatable. More preferably, the screw piles may be steel screw piles. Screw piles may be preferable to micropiles as screw piles are potentially removable and/or relocatable. Screw piles may even be recyclable. On the other hand, micropiles may be more permanent and/or may have increased structural integrity.

Any altemative foundation element may be envisioned however, as required.

The connection means, connection mechanism or connector 30 enables the or at least one said closure element 14 to be connected or connectable to the user-access element 12 and/or the cabin 20 thereof. The connection means 30 in-use enables the closure element 14 to be movable relative to the or a said access opening 22. More preferably, the connection means 30 comprises a pivot axis 44 about which the closure element 14 is pivotable. Preferably, the pivot axis 44 extends at or adjacent to a first longitudinal edge or a second longitudinal edge of a closure element 14. The pivot axis 44 of four closure elements 14 is shown as dashed lines in Figure 9. The connection means 30 preferably comprises one or more hinges 46, also shown in Figure 9, but alternatives are available. Optionally, the connection means may further comprise an actuator. The actuator may enable the movement of the closure element 14 to be powered.

The or each closure element 14 in-use openably closes at least in part the or at least one of the access openings 22. Each closure element 14 may alternatively be referred to as a door-element, door or barn door. A plurality of closure elements 14 may together close a common access opening 22, as shown. Each closure element 14 has a closure-element panel, wall, pane, or window 48 and a bird-support element 50.

The closure-element panel 48 is planar or substantially planar in the preferred embodiment, but non-planar or partly planar may be options. The closure-element panel 48 is preferably opaque, but non-opaque may be an option such as partly or fully transparent or translucent. The closure-element panel 48 has at least a first surface 52a and a second surface 52b.

The first surface 52a in use faces outwardly when the closure-element panel 48 is 30 received within or adjacent to an access opening 22. In other words, the first surface 52a in use faces outwardly to the ambient environment. The first surface 52a may be referred to as a colonial-seabird facing first surface or a bird facing first surface.

The second surface 52b is opposite the first surface 52a. In use, the second surface 52b faces inwardly. In other words, the second surface 52b in use faces inwardly towards the user-access area 18. The second surface 52b may be referred to as a user-facing second surface.

The closure-element panel 48 also has a first longitudinal edge 54a, a second longitudinal edge 54b and a width 56, indicated as a double-headed dashed arrow in Figure 9. For clarity, the terminology of a "longitudinal" edge will be maintained, even if a lateral edge of the closure-element panel 48 has a greater length than the longitudinal edge 54a,54b.

The bird-support element 50 in use extends from the first surface 52a as shown in Figure 10. The bird-support element 50 is adapted to support at least one bird thereon in-use. More preferably, the bird-support element 50 is be dimensioned and/or has the structural strength to support at least three birds thereupon. The bird-support element 50 may alternatively be referred to as a ledge, a shelf or a shelf element, a seabird-support element if the bird is a seabird, a colonial bird-support element if the bird is a colonial bird, or a colonial seabird-support element if the bird is a colonial seabird. The bird-support element 50 is preferably planar or substantially planar, although non-planar may be envisioned. The bird-support element 50 is preferably connectable with the closure-element panel 48 and/or the first surface 52a thereof, such as via one or more mounting brackets, although connected or integrally formed therewith is an option. The bird-support element 50 has a support surface 58.

The support surface 58 may be considered to be divided into three of more sub-surfaces 60 in the preferred embodiment, but any number of sub-surfaces, including one, two, four, or at least five may be envisioned. The three sub-surfaces 60 are delimitated by dotted lines in Figures 10 and 11. Each sub-surface 60 may receive a bird and/or a nest.

Each sub-surface 60 may be referred to as a sub-element, sub-section, a nest-receiving surface, or nesting-surface. The sub-surfaces 60 may optionally be indistinguishable from each other.

The bird-support element 50 meets with the first surface 52a at a junction 62. The bird-support element 50 and the first surface 52a form an angle. Said angle is preferably perpendicular. In the shown embodiment, one closure-element panel 48 and five such bird-support elements 50 are provided per closure element 14, but any alternative number of closure-element panels and/or bird-support elements per closure element may be envisioned, including none, one, two, or at least five.

Although the angle between the bird-support element 50 and the first surface 52a is preferably perpendicular, the angle may be non-perpendicular. For example, the bird-support element 50 may form an acute angle with the first surface 52a. More preferably, the angle may be in the range of 40° to 89°, although any value outside of this range may be envisioned. The angle is more preferably in the range of 70° to 89°, and even more preferably in the range of 80° to 89°. The preferred angle between the bird-support element 50 and the first surface 52a is 85° in this alternative embodiment. In other words, the bird-support element 50 may be offset relative to horizontal by an angle in the range of 1° to 50°, and more preferably in the range of 1° to 20°. More preferably yet, the bird-support element 50 may be offset relative to horizontal by an angle in the range of 1° to 10°, with the preferred offset angle being 5°. The angle may be acute in an in-use upwards direction to reduce the risk of a bird, and/or nest falling off the bird-support element 50. This may also replicate natural cliff angles. However, the angle may be acute in an in-use downwards direction. This may advantageously reduce the likelihood of liquid, such as rainwater pooling where the bird-support element 50 and the first surface 52a meet or anywhere on the bird-support element 50.

Optional features of the, each or at least one closure element 14 include: at least one viewing element 64, at least one window element 66, at least one capture-device aperture 68, and at least one feeding aperture 70, and at least one protective front wall, although any of the above may be omitted.

Each viewing element 64, each capture-device aperture 68 and each feeding aperture 70 comprises a through-hole, respectively, in the closure-element panel 48. As shown in the preferred embodiment, each closure element 14 has fifteen of each of the above, but any alternative number may be envisioned for any of the above features, such as none, one, two, at least three, five or any alternative number.

Each viewing element 64 is preferably square or rectangular, as shown, but non-square or non-rectangular are options. A viewing element 64 may alternatively be referred to as a hatch. Each viewing element 64 is circa 25.5cm wide and 30.5cm tall but any alternative dimensions may be envisioned. Each viewing element 64 enables a user positioned at or adjacent to the second surface 52b and/or inwardly of the closure element 14 to view through the viewing element 64 a bird-support element 50 and/or a bird received on the bird-support element 50. Each viewing element 64 may also enable a user to reach therethrough to access the bird-support element 50 and/or a bird thereupon. There is preferably at least one, and more preferably three viewing elements 64 positioned at or adjacent a common bird-support element 50, but any number including none, one, two or more than three may be an option. Each viewing element 64 may further comprise a closing element such that the viewing element 64 is preferably closed or closeable but this is optional such that the viewing element may remain open. The closing element here is preferably a window element 66, but non window elements may be envisioned, such as an opaque closing element.

The, each or at least one window element 66 may be a one-way or a two-way window. The, each or at least one window element 66 may be removably or non-removably connected to the viewing element 64 and/or closure-element panel 48. The window element 66 may be connected to the viewing element 64 and/or closure-element panel 48 by means of a window-connector, not shown. The window-connector may comprise any or any combination of: one or more hinges for pivoting the window element 66; one or more sliders or runners for slidably engaging the window element 66; one or more fasteners; and any other suitable engagement means.

Each capture-device aperture 68 is preferably an elongated rectangle or slit in side view, although any alternative shape may be envisioned. Each capture-device aperture, immobilisation opening, restraining or capturing throughbore 68 enables a user to insert a capture device therethrough to temporarily capture or restrain a bird on the bird-support element 50. This may be advantageous for scientific purposes, such as monitoring, measuring biometrics of the bird and/or tagging the bird. Each capture-device aperture 68 is preferably disposed along and/or at or adjacent the junction 62 between the first surface 52a and the bird-support element 50. In other words, each capture-device aperture 68 is positioned between a viewing element 64, and a bird-support element 50 in the shown embodiment.

In a modified embodiment, an in-use elongated rectangle or slit may be provided elsewhere than between the viewing element and the bird-support element. For example, a capture-device aperture may be provided extending perpendicularly or substantially perpendicularly to the bird-support element. This may provide an in-use vertical capture-device aperture in addition or instead of the shown capture-device aperture.

In a further modification, it may be envisioned that a capture-device aperture may be 30 provided by leaving a gap between a, preferably lower, edge of a window element and the edge of the associated viewing element, instead of providing a capture-device aperture which is distinct from a viewing element.

Each feeding aperture 70 enables a user to insert food therethrough and onto the bird-support element 50. Each feeding aperture 70 is preferably circular as shown but non-circular is an option. Optionally, a tubing or pipe portion or a half-pipe may be provided 72 at or adjacent the feeding aperture 70. Optionally, the tubing 72 may extend at least partly into and/or through the feeding aperture 70.

Although not shown in the drawings, a protective front wall or ledge may be provided additional protection and/or shade. The protective front wall or ledge may optionally also prevent or inhibit a bird from falling off or rolling off a bird-support element 50. This may be necessary if the acute angle between the bird-support element 50 and the first surface 52a is in a downward direction. The front wall or ledge may be positioned at or adjacent a cantilevered, front, or outer edge 73 of a bird-support element 50. The front ledge may be positioned or positionable on either surface of a bird-support element 50. In other words, the front ledge may extend upwards from the support surface 58 and/or downwards in use from the surface opposite the support surface 58. This may provide shade to the bird-support element 50 and/or a further bird-support element 50 below. The front ledge may be between 1 cm and 50 cm high although any height outside may be envisioned. More preferably, the front ledge may be between 5 cm and 30 cm, and is more preferably between 10 cm and 25 cm. Most preferably, the ledge is 20 cm high.

Further optional features of the bird-population compensation structure 10 include at least one protective side wall 74, at least one drainage hole, and at least one speaker, although any of the above may be omitted. Preferably, these optional features of the bird-population compensation structure 10 may be associated with the closure element 14.

If provided, the, each or at least one protective side wall 74 is positioned or positionable above, at, or adjacent to a first side or lateral edge 76 or a second side or lateral edge 78 of the bird-support element 50. Preferably, a protective side wall 74 is provided above, at, or adjacent to both lateral edges 76,78 of a bird-support element 50. Instead of or in addition to positioning at or adjacent to a lateral edge, the or a further protective side wall 74 may be positioned or positionable spaced-apart from a lateral edge of the bird-support element 50. Such a further protective side wall 74 may have a partitioning function and may be referred to as a partition. A partition may prevent or inhibit the spread of diseases and/or disease vectors. The, each or at least one said protective side wall 74, irrespective of its position, may comprise at least one of: an at least partly translucent material, an at least partly transparent material, a frosted material, and an opaque material. Transparent or translucent materials may enable light through, which can advantageously increase the local temperature, whilst protecting against the elements, such as rain and/or wind.

A translucent protective side wall 74 may also enable birds on either side to see each other. This may be beneficial for social stimulation. A suitable material may be Perspex (RTM), by way of example. The at least one protective side wall 74 is preferably removably connectable with the bird-population compensation structure 10 as this may enable users to selectively add and/or remove or reposition a protective side wall 74 for scientific experiments and/or to adapt the bird-population compensation structure 10 to a geographic site and/or changing weather conditions. The size of one or more subsurfaces 60 may be varied using a protective side wall 74, for example, for scientific experiments. More preferably, the bird-population compensation structure 10 comprises one or more engagement portions with which a protective side wall 74 may be engageable. The engagement portion may include a slot and/or a protrusion, by way of example only. A protective side wall 74 may be connectable with the bird-population compensation structure 10 only from the outside. However, it may alternatively be envisioned that a slot in the closure element 14 and/or in a wall 16 may be dimensioned such that a protective side wall 74 may be inserted and/or removed therethrough from the user-access area 18. It may alternatively be envisioned that a protective side wall 74 may be connected or integrally formed with the bird-population compensation structure 10. This may provide greater structural integrity against the elements.

At least one drainage hole or slot may be provided on, at or adjacent to a bird-support element 50. The at least one drainage hole may be in the first surface 52a and/or in the bird-support element 50. The drainage hole is preferably provided at or adjacent the junction 62 but spaced-apart therefrom is an option. For example, one or more drainage holes may be provided mid-shelf. A drainage hole, gap, slit may alternatively be provided by spacing apart the bird-support element 50 from the first surface 52a to leave a gap therebetween. The drainage hole or conduit may enable evacuation or drainage of a liquid, such as water, which may otherwise accumulate on the bird-support element 50. The drainage hole is preferably water-tight to prevent or inhibit any liquid moving through the drainage hole from entering or permeating through the bird-support element 50 and/or the closure-element panel 48. Liquid ingress may otherwise damage the structural integrity of the bird-population compensation structure 10 or parts thereof. Moisture reduction due to drainage may also reduce or eliminate the incidence of ticks, such as Ixodes uriae ticks in the birds using the structure 10.

At least one speaker may be provided. This may be used to play courtship and/or greeting vocalisations. The, each or a said speaker may be provided on or in the closure 35 element 14 and/or on or within the user-access element 12.

The bird-population compensation structure 10 also preferably comprises at least one climbing support 80, and at least one railing element 82, although either of these features may be omitted.

The at least one climbing support or climbing anchor element 80, shown in Figure 10 in-5 use enables climbing equipment to be engageable therewith. In turn, this enables a user to climb and/or abseil along an outer surface of the user-access element 12, such as to undertake maintenance such as structural inspections.

Alternatively or additionally, the climbing anchor element 80 may also be used as a safety mechanism for fall arrest. Preferably the climbing support 80 comprises at least one loop element, hoop element, hook element, or climbing piton for receiving a climbing rope, carabiner, or other climbing equipment. The or each climbing support 80 may be provided or positionable on the cabin 20 and/or on the spacer element 26 of the user-access element 12. Alternatively or additionally to either of the above uses of the climbing anchor element 80, whilst the stairs are the primary access means, the climbing anchor element 80 may provide a secondary way of climbing and/or exiting the user-access area 18, such as by users preferably having suitable climbing qualifications. Having a secondary access route may increase safety. For example, during a fire, being able to quickly abseil down the outside of the structure may be preferable to a staircase as the staircase may be filled with flames and/or smoke. The structural integrity of the staircase may also be compromised by the fire.

The at least one railing element 82 is integrally formed with, connected, or connectable to the user-access element 12. The at least one railing element 82 may form and/or be part of a fall arrest system. The fall arrest system may optionally further comprise a safety latch and/or pivot, such as a gate or door with a latch. The at least one railing element 82 and/or fall arrest system may even negate the need for a user to connect themselves to the structure 10 via an attachment means or mechanism, such as a harness and connector, although these features may be envisioned for additional safety.

The, each or at least one railing element 82 is preferably configured or configurable to extend at least partly across the or a said access opening 22. The, each or at least one railing element 82 in-use thereby increases safety by preventing or inhibiting a user from falling through an open or partly open access opening 22 and out of the cabin 20. Preferably, the, each or at least one railing element is positioned or positionable outwardly of an access opening 22 but at or inwardly of an access opening 22 is an option.

In use, a user desiring to manage a bird population needs to locate a suitable site and assemble a bird-population compensation structure 10.

The user obtains a bird-population compensation structure 10. The bird-population compensation structure 10 may be selected based on a particular geographic siting.

Alternatively, the selection of the suitable site may be at least in part selected to accommodate a specific bird-population compensation structure 10. The structure 10 may be provided as a kit of parts. Preferably, the structure 10 comprises a plurality of bird-support elements 50.

In a generalised embodiment, the user selects a geographic siting location, preferably based on at least one environmental and/or biological parameter. The at least one environmental and/or biological parameter may include at least one of: bird biology data; position data of a body of water and/or a further building relative to the bird-population compensation structure 10; terrain data; topography data; time-series data about at least one of: wind, solar irradiation, sun path, sun azimuth, sun elevation, and shade; proximity to an existing colonial seabird population; proximity to a predator population; and proximity to a habitat suitable for a predator. If the bird is a colonial seabird, the bird biology data is colonial seabird biology. Any additional or alternative parameter may be included. Bird biology data may include weight and/or body dimensions by way of example only.

There may be one or a plurality of suitable locations to select from. The geographic siting location is preferably located on land. However, it may easily be envisioned that the geographic siting location may be offshore and/or underwater, all or at least part of the time. For example, if the geographic siting location is installed in a tidal area, the geographic siting location may be underwater during at least part of a tidal cycle.

Optionally, the geographic siting location is selected to be adjacent to an existing bird population. The existing bird population may comprise an, optionally urban, colony of kittiwakes. Preferably, the geographic siting location is selected such that the bird-population compensation structure 10 is in or adjacent to a, preferably tidal, body of water but this is optional. Preferably, the body of water is clearly visible from the bird-population compensation structure 10 or at least parts thereof. Optionally, the heights and/or positions of one or more surrounding landscape element, such as one or more buildings and/or a natural element, such as a cliff, are determined. More preferably, the characteristics of the surrounding landscape which may provide shade are determined, but this is, once again, optional.

Preferably, any location in which a predator is present and/or which provides a suitable habitat for a predator is avoided, but this is optional and/or may not be feasible. More preferably, any location with an existing or potential avian predator and/or roosting or nesting habitat suitable for the avian predator is avoided. Predators may include any avian predator, such as corvids, gulls or any other bird species. Gulls may include herring gulls, great black-backed gulls or any other gulls.

Optionally, the final height of the bird-population compensation structure 10 may be determined and/or altered. This may be beneficial to determine and/or adjust the height of the or each bird-support element 50 relative to the ground level and/or the surface of the body of water. Additionally or alternatively, the final height of the bird-population compensation structure 10 can be determined and/or altered to take the local landscape into account.

Preferably, the position and/or direction of the, preferably tidal, body of water relative to the proposed geographic siting location is identified, but this is optional.

Once the geographic siting location has been selected, the user determines an appropriate orientation of at least one bird-support element of the bird-population compensation structure 10. The orientation may depend on at least one environmental and/or biological parameter. The at least one environmental and/or biological parameter may be the same as listed above for determining a suitable location. Additionally or alternatively, the orientation may depend on at least one of: temperature, wind exposure, rain exposure, sun exposure, visibility of the or a body of water from at least one bird-support element 50, and the provision of a bird-support element 50 with at least one protective side wall 74. Sun exposure includes at least one of: solar irradiation, sun path, sun ray, sun azimuth, sun elevation, shade data, and any other suitable metric. The temperature is preferably the ambient air temperature.

In a preferred embodiment, a user carries out the following steps, preferably but not necessarily in the following order. Furthermore, any of these steps may be omitted and/or additional steps may be carried out. The user obtains wind data, and more preferably industry-accepted time-series wind data. The wind data is preferably but not necessarily obtained together with terrain information. Furthermore, the user preferably also obtains sun exposure data, and more preferably industry-accepted time-series sun exposure data. The sun exposure data may include any of: solar irradiation data, sun path data, sun ray data, sun azimuth, sun elevation, and shade data. The sun exposure data is preferably but not necessarily obtained together with terrain information.

The user determines all or at least one of: typical incubation dates, typical hatching dates, and typical fledging dates for the proposed geographic siting location. The typical hatching date at least, may be the most important in terms of determining the thermoregulation risk to eggs and/or newly hatched chicks, young and/or juveniles.

The user then orients the bird-population compensation structure 10 or a model or representation thereof such that such that body of water is preferably visible from at least one, and more preferably two walls or wall-sections 16 of the cabin 20.

As each wall or wall section 16 is oriented in a different direction, each wall or wall section 16 of the cabin 20 is labelled according to a compass direction which the wall or wall section 16 faces or substantially faces; or would face or substantially face following assembly. As there are preferably four walls 16, the walls 16 are labelled: North (N), South (S), East (E), West (VV), or North-West (NW), North-East (NE), South-West (SW), and South-East (SE).

The user estimates the exposure of each wall or wall sections 16 to wind. More preferably, for wind data, the user estimates the wind exposure over all the duration of the breeding season, although the estimation may only be over a portion, major or minor, of the breeding season duration, or the estimation may extend of a period greater than the breeding season.

The breeding season is preferably defined as starting from an egg incubation date and 20 ending on the or a fledging date. The fledging date is defined as the date a juvenile departs from the nest. Preferably, the date is the earliest date in either or both cases, but could easily be a later date, the last date, or an average date in either or both cases.

Preferably, the exposure to wind estimates is estimated using wind data. The wind data is preferably weekly data but any other frequency such as monthly, or daily may be envisioned. The wind data preferably comprises wind direction, wind speed, air temperature data, although any of the above may be omitted and/or additional wind parameters may be included.

Young birds and/or juveniles typically have poor thermoregulation. Thus, any, and preferably all of: temperature, wind, and rain are factors that greatly affect the survival during at least one of: the incubation period, during the first approximately ten days after hatching and during a, optionally circa ten-day, post-fledging period. Adult birds may also enter a period of temporary hypothermia when incubating eggs on the nest during low temperature events. Any extreme winds and/or extreme temperatures, whether high or low, in any or all the above periods may be weighted more highly in the wind exposure estimates.

Based on the wind exposure estimates, the user ranks the wall or wall sections 16 from most to least exposed to wind, and more preferably to extreme and/or cold wind.

Instead of, or in addition to wind, the user may estimate the exposure of each wall or wall sections 16 to sun. Sun exposure may include any of: solar irradiation, sun path, sun azimuth, sun elevation, shade and any other metric.

The user repeats similar steps for sun. In other words, the user estimates the sun exposure over a period. The period is preferably all the duration of the breeding season, but any alternative period may be envisioned. Preferably, the sun exposure estimates are based on data relating to sun exposure, also referred to as sun exposure data. The sun exposure data is preferably weekly data but non-weekly data is an option. The sun exposure estimates also take into account topography; shade, such as from a building; and the height of the bird-support element 50, although any of the above may be omitted.

Similarly to extreme temperature and/or wind, sun exposure is another factor which greatly affects bird survival during the incubation period and/or during the, optionally ten-day, post-fledging period. Thus, any sun exposure extremum, whether high or low, during one or both periods may be weighted more highly in the sun exposure estimates.

Based on the sun exposure estimates, the user ranks the wall or wall sections 16 from most to least hours of exposure to the sun, and more preferably to any extremes of sun exposure. The user may need to adapt the configuration of the bird-population compensation structure 10 as a result of the wind and/or sun exposure estimates of each wall or wall sections 16.

For example, the wall or wall section 16 having the highest exposure to cold gusty winds is not likely to be successful unless that wall or wall section 16 has a minimum number of hours of sun exposure to counter heat losses, such as due to experiencing extreme cold winds from one direction during the night-time and early moming. The minimum number of hours of sun exposure may be from at least one hour after sunrise until at least 10am. Having at least partly translucent side walls 74 permitting at least some light, and therefore heat, such as in the form of solar irradiation therethrough, may be the difference between survival and death of an incubated egg, and/or young bird.

If one of the walls or wall-sections 16 is deemed to have particularly high exposure to wind, the, each or at least one bird-support element 50 depth may be reduced. For example, the depth of the bird-support element 50 is preferably at least 30 cm deep but may be reduced to have a depth between 5 cm and 30 cm, and more preferably between 10 cm and 25 cm. Most preferably, the depth is 20 cm. Whilst a reduced depth reduces available space, reducing the depth of the bird-support element 50 may also reduce the ability of predators, such as gulls, to land on the bird-support element 50. The increased mortality due to the wind and/or temperature may be at least partly offset by the reduced predation.

An example of high exposure to wind is when a wall or wall section 16 experiences winds having a velocity of at least 10 km/hour. The velocity may be or a single datapoint or an 10 average velocity, such as over at least part of the breeding season and/or young chick phase.

Based on the sun and/or wind exposure estimates and the orientation of each wall or wall section 16, the user determines the configuration of the or each closure element 14 of each wall or wall section 16. In other words, the user determines for each wall or wall section 16 whether to use a bird-support element 50 extending perpendicularly or at an acute angle relative to the first surface 52a and/or whether to provide at least one side wall 74.

A bird-support element 50 and at least one side wall 74 at or adjacent either lateral edge of the bird-support element 50 may be referred to as a "boxed" bird-support element 50 for clarity. If at least one side wall 74 is provided along the length of the bird-support element 50, the bird-support element 50 may be referred to as a "partitioned" bird-support element 50 for clarity. A bird-support element 50 may be both "boxed" and "partitioned". A bird-support element 50 having no side wall 74 may be referred to as a "simple" or "linear" bird-support element 50 for clarity.

Furthermore, the or each closure element 14 and/or the or each bird-support element 50 may optionally be omitted from any wall 16 which has a high or the highest sun exposure. This may typically be a S or SW-facing wall 16. Alternatively or additionally, the closure element or elements 14 of one or more walls 16 with a high sun exposure may be provided with one or more simple bird-support elements 50. These measures may increase survival of young birds by reducing or preventing the risk of overheating. Natural shade and/or shade from neighbouring buildings, particularly but not necessarily during the hottest time of the day may be taken into account when determining the configuration of the closure elements 14. High sun exposure may be defined as receiving direct continuous solar irradiation for a prolonged period which induces bird behaviours which serve to either minimise radiative heat gain, or increase evaporative cooling, including but not limited to panting, gular fluttering, wing spreading and body positioning.

In view of the above, typically, a wall 16 having a low wind exposure and being protected from high sun exposure, is fitted with one or more simple bird-support elements 50.

One or more bird-support elements 50 on a wall or wall section 16 which has a higher exposure to wind and/or cold may be fitted with one or more side walls 74 and/or the bird-support element or elements 50 may be acute, but these features are optional.

A wall 16 facing a high or the highest sun exposure, such as a directly south or southwest facing wall, is typically devoid of any bird-support elements 50. A wall having the second-highest sun exposure, such as an obliquely south facing wall, may be provided with one or more simple bird-support element 50, and optionally one or more front ledges for shade. All the above may be amended according to the exact location, terrain, position and/or visibility of the body of water, sun and/or wind exposure.

The user assembles the bird-receiving compensation structure 10 at or adjacent to the determined geographic siting location. Furthermore, the bird-receiving compensation structure 10 is preferably assembled in the determined orientation, but this feature may be omitted. For example, the bird-population compensation structure 10 or part thereof may be movable. By way of example, part of the bird-population compensation structure 10, such as the cabin and/or the spacer element may be rotatable, such as by comprising a rotation mechanism. Preferably, the bird-population compensation structure 10, once assembled, has a plurality of walls or wall sections facing different directions.

To assemble the bird-receiving compensation structure 10, the user completes the following steps. At least some of, and preferably all of the assembly steps occur at the geographic siting location. However, it may easily be envisioned that all or any part of the bird-population compensation structure 10 may be assembled offsite and brought to the site after assembly.

The foundation element 28, if provided, is installed. This may involve any of: assembling supporting beams together; drilling; digging; and pouring concrete. For example, one or more piles and/or micro-piles may need to be anchored into or onto the ground surface.

The spacer element 26, if provided, is assembled on or adjacent to the foundation element 28 and/or a ground surface at the geographic siting location.

The user-access element 12 is assembled or connected onto the foundation element 28.

Connection of the cabin 20 with the foundation element 28 and/or a second structure is preferably indirect, for example, via the spacer element 26. However, a direct connection may be possible, for example, if no spacer element is provided.

If provided, the roof element 24 and/or railing element or elements 82, may be assembled and connected with the user-access element 12 at any stage, as required.

Furthermore, the climbing support 80 if provided, is integrally formed with the user-access element 12. However, non-integrally formed is an option. In this alternative, the climbing support may be added to the user-access element 12 at any stage.

The closure element 14 may be partly or fully assembled prior to or after being received in the or an access opening 22. Assembly of the closure element 14 may include the 10 following steps.

If a closure element 14 comprises a plurality of closure-element panel 48, the closure-element panels 48 are assembled together. If any viewing element 64 is provided, the viewing element 64 may optionally be closed by a window element 66 if provided. A tube or tube portion 72 may optionally be received in, through, or around the, each or at least one feeding aperture 70.

Optionally, one or more protective side walls or surfaces may be integrally formed with, connected, or connectable to a closure-element panel 48 and/or to a bird-support element 50. The panel 48 and/or bird-support element 50 may comprise an engagement means for enabling to a protective side wall 74 to be removably engageable therewith.

The protective side wall 74 may be provided at or adjacent to one or both lateral edges of a bird-support element 50. Additionally or alternatively, a protective side wall 74 may be provided along a longitudinal extent of the bird-support element 50. In other words, the protective side wall 74 may be provided spaced-apart from the lateral edges of the bird-support element 50. The protective side wall 74 may therefore function as a partition, separating or partitioning more clearly two or more sub-surfaces 60 of the support surface 58 of the bird-support element 50. This may improve the protection from the elements and/or predators. This may also enable more birds to be supported on a given bird-support element 50.

The or each closure element 14 may be connectable or connected via a connection means 30 to the user-access element 12. In the shown embodiment, the connection means 30 comprises at least one, and preferably a plurality of hinges. The connection means 30 is preferably of the same type for all closure elements 14 but different types may be envisioned.

There may be a plurality of closure element 14 receivable in a common access opening 22. As shown, two such closure elements 14 are receivable in a common access opening 22. The connection means 30 may be provided on the same edge of two adjacent closure elements 14 but non-adjacent edges may be an option. Preferably, the connection means 30 alternates side between adjacent closure elements 14 but non-alternating is an option.

In the shown embodiment, at least one, and preferably three walls of the user-access element 12 are fitted with at least one, and preferably four closure elements 14, each having at least one, and preferably five bird-support elements 50. Additionally, one or more closure elements 14 of at least one of the walls 16 further comprises at least one, and preferably two protective side walls 74 associated with one or more bird-support elements 50.

A further said wall 16 is preferably devoid of any closure elements 14 and/or of bird-support elements 50. Instead, the further wall 16 comprises at least one, and here two light-permitting openings 21. The configuration of the walls 16 and/or closure elements 14 may determine at least in part the orientation of the user-access element 12. In other words, which walls 16 are fitted or devoid of closure elements 14 and/or which closure elements 14 comprise a side wall 74 may affect, be affected by, determine or be determined by the orientation of the user-access element 12.

Once the user-access element 12 is assembled, one or more birds may be received on the bird-support elements 50. A user can monitor the or each bird via a viewing element 64 if provided. Thus, the user may be referred to as a monitoring worker, or an environmental professional. An environmental professional may include but not be limited to any of: a scientist, an ecologist, a wildlife biologist, and an ornithologist undertaking bird monitoring work. Bird monitoring work may include but not be limited to any of: tagging and ringing birds, observational studies, biological and physiological studies, biometrics studies and behavioural studies; and undertaking supplementary feeding of birds via feeding hole. The plurality of users who monitor one or more birds may be referred to as a monitoring workforce.

Food can be inserted through the or a feeding aperture 70. Increased availability of food may increase the survival rate of a bird. As feeding each bird through each feeding aperture 70 is laborious, the number of viewing elements 64 and/or feeding apertures 70 may be increased or decreased to match the capacity of the monitoring workforce. In a further modification, the feeding aperture 70 may be part of a feeding system which may enable food to be distributed to a plurality of feeding apertures 70 and/or to a plurality of bird-supporting elements 50 in one step. The feeding system may, for example, comprise tubing connected to several feeding apertures, by way of example only.

To immobilise a bird using the capture-device aperture 68, the user may require an 5 immobilising or capture device, such as a noose, noose element, hoop, clamp, or similar device. The immobilising device is inserted through the capture-device aperture 68. The immobilising device is positioned around a body part of the bird, such as the neck, body, or, preferably, a leg. The immobilising device may need to be actuated into an engaging condition to grasp or hold the bird and prevent the bird from flying away. In the case of a 10 noose element, the noose element may need to be temporarily tightened.

As birds remain on the bird-receiving compensation structure 10, the bird-support elements 50 become dirty and malodorous from guano. The insalubrity may also encourage the spread of diseases or parasites It is therefore advantageous to be able to clean the bird-support elements 50.

Various methods can be used to clean the bird-support elements 50.

A user may climb outside of the user-access element 12 using the climbing support 80. Whilst an option, this requires the user to have relevant climbing qualifications and competency. Climbing may be impractical and potentially dangerous, particularly in poor weather conditions.

The bird-support elements 50 could alternatively be cleaned by opening each viewing element 64 and reaching therethrough. This is a safer option than climbing.

The advantage of the present invention is that the closure element 14 is movable relative to the access opening 22 to enable the bird-support element or elements 50 to be selectively movable into the user-access area 18. In the preferred embodiment, this is done by pivoting the closure element 14 about its hinges inwards. This movement is indicated as Arrow A in Figure 12. The entirety of the bird-support element or elements 50 attached to the closure-element panel 48 can be easily accessed within the cabin and from the front. In other words, the bird-support element or elements 50 are selectively positionable above a floor surface of the cabin 20.

This enables the user to access the bird-support element or elements 50 safely from within the cabin, in any weather, without requiring the user to be a qualified and competent climber. The user does not need to strain to reach through the viewing element 64 to clean a bird-support element or elements 50. The bird mess removed from the bird-support element or elements 50 may be discarded or retained for alternative use.

The mobility of the closure element 14 also enables a user to easily carry out repairs and/or alter the configuration of a closure element 14, as required. For example, a user 5 can alter the number of bird-support element or elements 50 and/or add or remove one or more protective side walls 74. This may be advantageous for experimental purposes.

Optionally, the bird-receiving compensation structure 10 may be altered at any point. Alteration may include at least one of: moving the structure or part thereof; adding any of: at least one protective side wall, at least one bird-support element or colonial seabird-support element, at least one viewing element, at least on window element, at least one capture-device aperture, at least one feeding aperture; and removing any of: at least one protective side wall, at least one bird-support element or colonial seabird-support element, at least one viewing element, at least on window element, at least one capture-device aperture, at least one feeding aperture. For example, it may be desirable to experimentally test the effect of a bird-support element having a different material, colour, and/or dimensions on survival.

Whilst climbing and/or abseiling is preferably avoided to access and clean the bird-support elements 50, climbing and/or abseiling may however be necessary, for example to carry out maintenance. A user who carries out maintenance work may be referred to as a maintenance worker. At least one and preferably all maintenance workers are competent climbers and/or have climbing qualifications such as rope access work and/or working with heights. Such a worker may be referred to as a climber. The plurality of maintenance workers may be referred to collectively as a maintenance workforce.

In contrast, it is not necessary for the monitoring worker to be a competent climber and/or 25 have any such climbing qualifications. A monitoring worker is not excluded from having climbing qualifications however.

Referring now to Figure 13, there is shown a second embodiment of a bird-population compensation structure 110.

Features of the second embodiment of the bird-population compensation structure 110 30 which are similar to those of the first embodiment of the bird-population compensation structure 10 have the same or similar reference numerals with the prefix "1" added.

The second embodiment of the bird-population compensation structure 110 is similar to the first embodiment, having a user-access element 112, a closure element 114, a wall 116, a user-access area, an access opening, a roof element 124, a spacer element 126, a foundation element 128, a connection means, a staircase or ladder 132, a pivot axis, a closure-element panel 148, a bird-support element, a first surface, a second surface, a first longitudinal edge, a second longitudinal edge and a width, a viewing element, a window element, a capture-device aperture, a feeding aperture, a protective side wall, and a drainage hole, a climbing support, and a railing element, but any of these features may be omitted and/or a plurality of any of the above features may be provided. Detailed description of the common features is omitted for brevity.

In the second embodiment, there are preferably at least two cabins 120, as shown. A 10 first of the two cabins 120 preferably at least partly overlaps and/or overlies the or a second said cabin 120. Furthermore, the two cabins 120 may be integrally formed with each other, connected or connectable to each other and/or abuttable against each other.

It may alternatively be envisioned that a first cabin may be spaced apart from the or a further said cabin, for example by a further spacer element.

Whilst all the above embodiments comprise a tower element, it may easily be envisioned that a non-tower spacer element may be provided and/or the spacer element may be omitted entirely. A non-tower spacer element may include, for example, a wall.

Although preferably the number of capture-device apertures, feeding apertures and viewing elements is the same, different numbers may be provided, as required. It may 20 be envisioned that any of a said capture-device aperture, feeding aperture, and viewing element may be provided in a said wall instead of a closure element.

For example, it may be envisioned that a capture-device aperture may be associated with a plurality of viewing elements and/or a plurality of bird-support elements. Similarly, one viewing element may be associated with a plurality of bird-support elements and/or a plurality of capture-device apertures. Each bird-support element may alternatively be associated with one, two or at least three viewing elements; and/or with one, two or at least three capture-device apertures.

The or each bird-support element is preferably integrally formed with or connected to the or a closure-element panel. However, in a modification, the, each, or at least one bird-support element may be separably connectable thereto. In this alternative, an engagement means may be required to engage the bird-support element and the panel. Such an engagement means may comprise male and female engagement portions. For example, a slot, groove and/or a protrusion may be provided in or on the panel, engageable with a complementary portion of the bird-support element. One or more slots may even be dimensioned such as that a side wall and/or a bird-support element may be inserted therethrough from within the user-access area, without requiring the closure element to be opened.

It may easily be envisioned that an additional or alternative railing element may not extend across an access opening. Instead, the railing element may be positioned or positionable within the user-access area. A user may need to connect themselves to the railing element, such as by wearing a harness and by being connectable to the railing element via a rope or rope element.

Whilst the pivot axis is preferably at or adjacent a longitudinal edge, the pivot axis may be positioned spaced-apart from both the first longitudinal edge and the second longitudinal edge of the closure element and/or a closure-element panel thereof. The pivot axis may be or be substantially equidistant from both longitudinal edges. Alternatively, the pivot axis is positioned at or adjacent to a third of the width of the closure element and/or a closure-element panel from one of the longitudinal edges. Although hinges are preferred, non-hinges may be envisioned. For example a pivot axis may be provided by an axle extending along and/or through a closure-element panel. It will be understood that the axle may be integrally formed with the panel and/or may be a virtual axle. The axle may be disposed or positionable anywhere along the width of the closure-element panel. The position of the axle may be selectable. For example, the axle may be provided centrally. In other words, the axle may be equally spaced-apart from either longitudinal edge of the closure-element panel. Alternatively, the axle may be non-equally spaced apart relative to the longitudinal edges of the closure-element panel. For example, the axle may be positioned along a third of the width.

Optionally, a closure element may need to have at least one slit, regardless of whether the railing element is positioned outwardly or inwardly relative to the access opening and/or relative to the closure element. The or each slit may need to be suitably dimensioned and positioned to permit a said railing element therethrough upon movement of the closure element such as during rotation about a central axis.

In a further modification, in addition to or instead of pivotable movement, the closure element may be non-pivotably movable. For instance, the connection means may comprise a translation means for enabling translation of the closure element relative to the access opening. The translation means may comprise at least one rail or runner along which the connection means is translatable. Preferably, the at least one rail or runner is linear. Thus, the closure element may be linearly translatable.

Bird mess and in particular guano, is a naturally-produced fertiliser. The carbon footprint of guano may be lower than artificially-produced fertilisers. Therefore, as an alternative to being simply discarded, the bird mess may be harvested and optionally 5 commercialised for use as a fertiliser. The bird-population compensation structure 10 in this case may alternatively be referred to as a fertiliser-harvesting structure, a guano-harvesting structure. The structure may optionally include additional features to facilitate fertiliser harvesting. For example, the structure may further comprise one or more harvesting features, such as a net element. The net element may catch nesting material 10 and/or bird mess. A tube or tube-like element extending from the cabin or conveyor belt to the ground surface may enable a user to insert bird mess therein, thereby avoiding climbing down the user-access element 12 carrying bags of bird mess.

Although a preferred shape in lateral and/or longitudinal cross-section or in front and/or side view may have been indicated for any of the above features in any of the above embodiment, it may easily be envisioned that an alternative shape may be envisioned in lateral and/or longitudinal cross-section or in front and/or side view, such as curved, part curved, non-curved, planar, linear, circular, oval, ovoid, polygonal, such as triangular, square, rectangular, pentagonal, hexagonal, octagonal, or any other polygon, whether regular or irregular, whether chamfered and/or truncated or any abstract shape. For example, user-access element circular or at least in part curved in transverse cross-section may be provided.

It is therefore possible to provide a bird-population compensation structure or a colonial-seabird nesting structure if provided for colonial seabirds, such as kittiwakes. The structure provides a nesting habitat to increase the size of a bird population in one location. This may be advantageous to offset a reduction in population size of the same species in another location. Such a reduction may be due to an industrial project, such as a wind turbine or destruction of an existing nesting habitat for the bird species. The bird-population compensation structure advantageously increases safety and facilitates cleaning and access to the bird-support element by enabling the bird-support element to be movable into the user-access area. The structure may additionally or alternatively improve breeding productivity. It is therefore also possible to provide a method of selecting an appropriate location and orientation of a bird-population compensation structure or a colonial-seabird nesting structure to increase the usage by birds and bolster the population size.

The words 'comprises/comprising' and the words 'having/including' when used herein with reference to the present invention are used to specify the presence of stated features, integers, steps or components, but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.

The embodiments described above are provided by way of examples only, and various other modifications will be apparent to persons skilled in the field without departing from the scope of the invention as defined herein.

Claims

Claims 1. A method of siting and assembling a colonial-seabird nesting structure, the method comprising the steps of: a] providing a colonial-seabird nesting structure having a plurality of colonial seabird-support elements facing in the same or different directions; b] determining a geographic siting location based on one or more of: colonial seabird biology data; position data of a body of water and/or a further building relative to the colonial-seabird nesting structure; terrain data; topography data; time series data about at least one of: wind, solar irradiation, sun path, sun azimuth, sun elevation, and shade; proximity to an existing colonial seabird population; proximity to a predator population; and/or proximity to a habitat suitable for a predator; c] determining an orientation of the said colonial seabird-support elements of the colonial-seabird nesting structure depending on one or more of: temperature, wind exposure, rain exposure, sun exposure, visibility of the or a body of water from at least one said colonial seabird-support element, and/or the provision of a colonial seabird-support element with at least one protective side wall; and d] assembling the colonial-seabird nesting structure at the determined geographic siting location and with the determined orientation.
2. A method for siting and assembling a bird-population compensation structure, the method comprising the steps of: a] providing a bird-population compensation structure; b] selecting a geographic siting location based on at least one environmental and/or biological parameter; c] determining an orientation of at least one bird-support element of the bird-population compensation structure depending on at least one of: temperature, wind exposure, rain exposure, sun exposure, visibility of a body of water from a said bird-support element, and the provision of a bird-support element with a protective side wall; and d] assembling the bird-receiving compensation structure at the determined geographic siting location and with the determined orientation.
3. A method as claimed in claim 1 or 2, comprising a further step of altering the colonial-seabird nesting structure or bird-population compensation structure by at least one of: moving the structure or part thereof; adding any of: at least one protective side wall, at least one bird-support element or colonial seabird-support element, at least one viewing element, at least on window element, at least one capture-device aperture, at least one feeding aperture; and removing any of: at least one protective side wall, at least one bird-support element or colonial seabird-support element, at least one viewing element, at least on window element, at least one capture-device aperture, at least one feeding aperture.
4. A colonial-seabird nesting structure for at least in part increasing breeding productivity and providing a safe access space for a user, the colonial-seabird nesting structure comprising: a user-access element having at least one wall comprising an access opening, the at least one wall defining a user-access area of the user-access element; a closure element for openably closing the access opening in the said wall, the closure element having: a colonial-seabird facing first surface which in use faces outwardly to the ambient environment, a user-facing second surface which is opposite the first surface and which in use faces inwardly towards the user-access area, a colonial seabird-support element extending from the said first surface and which is adapted to support at least one bird and/or bird-nesting structure thereon, a capture-device aperture for enabling insertion of a bird-capture device therethrough to temporarily capture a bird supported by the colonial seabird-support element, and an openable viewing element that can be opened to retrieve a captured bird, the closure element being movable relative to the access opening to enable the colonial seabird-support element to be selectively movable into the user-access area.
5. A structure as claimed in claim 4, further comprising a tower element for supporting at least the user-access area.
6. A structure as claimed in claim 4 or claim 5, wherein the closure element comprises a further viewing element.
7. A structure as claimed in any one of claims 4 to 6, wherein the or each viewing element is closable by a window element.
8. A structure as claimed in any one of claims 4 to 7, further comprising a connection means for connecting the closure element to the at least one wall.
9. A structure as claimed in claim 8, wherein the connection means comprises a pivot axis about which the closure element is pivotable.
10. A structure as claimed in claim 8 or claim 9, wherein the connection means comprises at least one hinge.
11. A structure as claimed in claim 9, wherein the pivot axis is positioned spaced-apart from both a first longitudinal edge and a second longitudinal edge of the closure element.
12. A structure as claimed in claim 11, wherein the pivot axis is or is substantially equidistant from both longitudinal edges.
13. A structure as claimed in claim 11, wherein the first longitudinal edge is spaced apart from the second longitudinal edge by a width and the pivot axis is positioned at or adjacent to a third of the width from one of the longitudinal edges.
14. A structure as claimed in any one of claims 4 to 13, further comprising a railing element which extends or is configurable to extend across the access opening.
15. A structure as claimed in any one of claims 4 to 14, wherein the closure element further comprises a feeding aperture for providing food therethrough.
16. A structure as claimed in any one of claims 4 to 15, wherein the closure element comprises a drainage hole at or adjacent the colonial seabird-support element.
17. A structure as claimed in any one of claims 4 to 16, wherein the closure element further comprises a protective side wall.
18. A structure as claimed in claim 17, wherein the protective side wall is positioned or positionable at or adjacent to a lateral edge of the colonial seabird-support element.
19. A structure as claimed in claim 17 or claim 18, wherein the or a further protective side wall is positionable spaced-apart from a lateral edge of the colonial seabird-support element.
20. A structure as claimed in any one of claims 17 to 19, wherein the or at least one said protective side wall includes a material that is at least in part light-transmissible.
21. A structure as claimed in any one of claims 4 to 20, wherein the colonial seabird-support element meets the first surface at an acute angle.
22. A structure as claimed in any one of claims 4 to 21, further comprising a staircase which is associated with the user-access element.
23. A structure as claimed in any one of claims 4 to 22, further comprising a climbing anchor element for enabling climbing equipment to be engageable therewith.
24. A bird-population compensation system for at least in part managing a bird population, the bird-population compensation system comprising: a support structure supporting at least one wall comprising an access opening, the at least one wall defining a user-access area of the support structure; a closure element for openably closing the access opening, the closure element having: a bird-facing first surface which in use faces outwardly, a user-facing second surface which is opposite the first surface and which in use faces towards the user-access area, and a bird-support element extending from the first surface and which is adapted to support at least one bird and/or bird-nesting structure thereon, the closure element being movable relative to the access opening to enable the bird-support element to be selectively movable into the user-access area for safe access by a user.